/Engine/Plugins/Media/MediaIOFramework/Source/MediaIOCore/Public/MediaCapture.h
Stop the actual capture if there is one. Then capture every frame for a TextureRenderTarget2D. The TextureRenderTarget2D needs to be of the same size and have the same pixel format as requested by the media output.
True if the capture was successfully started
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Media|Output") bool CaptureTextureRenderTarget2D ( [UTextureRenderTarget2D](API\Runtime\Engine\Engine\UTextureRenderTarget2D) * RenderTarget, [FMediaCaptureOptions](API\Plugins\MediaIOCore\FMediaCaptureOptions) CaptureOptions )